tbuckley/cabot-search huggingface dataset:
Abstract P1156: Potential Role Of Ferroptosis In Duchenne Muscular Dystrophy-associated Cardiomyopathy
Authors: Nadezhda Fefelova, Satvik Mareedu, Sri Harika Pamarthi, Gopal J Babu, Judith K Gwathmey, Lai-Hua Xie
Journal: Circulation Research (2023)

Background and Aims: Duchenne muscular dystrophy (DMD) is the most common and fatal form of muscular dystrophy. DMD-associated cardiomyopathy (DMD-CM) is a major cause of morbidity and mortality in patients with DMD. Ferroptosis, a new type of regulated cell death characterized by iron-dependence and the accumulation of cell membrane lipid peroxidation, has been manifested in various cardiovascular disease conditions. However, ferroptosis has not been studied in DMD-CM. Here, we aim to determine whether ferroptosis play a potential role in DMD-CM. Methods and Results: We used a dystrophin/utrophin double knockout (mdx:utr -/- ) mouse model that displays clinical signs of DMD and DMD-CM. We performed RNA isolation from the ventricles of 3-month-old wild type (WT) and mdx:utr -/- mice (n=3) and performed RNA-Seq analysis. We found alterations of ferroptosis-related pathways such as GTP cyclohydrolase 1, transferrin receptor, glutamine transporter SLC38A1, heme oxygenase-1 (HMOX-1), and arachidonate 5-lipoxygenase (ALOX5) pathways in mdx:utr -/- hearts compared to WT hearts. Western blots confirmed the upregulation of ALOX5 and downregulation of HMOX-1, ferroptosis suppressor protein 1, and NADPH oxidase 4 in mdx:utr -/- hearts, while there was no change in glutathione peroxidase 4 (GPX4) levels. We also observed an increased level of lipid peroxidation in mdx:utr -/- hearts compared to WT as estimated by the level of malondialdehyde. Live/dead viability assays demonstrated a higher cell death rate in cardiomyocytes from mdx:utr -/- mice (53.7±7.2%, n=24) compared to those from WT mice (11.7±1.1%, n=17, p&lt; 0.01) under control conditions. The observed cell death in mdx:utr -/- cardiomyocytes was efficiently prevented by the selective ferroptosis inhibitor ferrostatin-1 (10 μM) (7.4±1.5%, n=9, p&lt;0.01), but not by the apoptosis inhibitor emricasan (20 μM) (56.0±1.6%, n=3, NS). Similarly, higher death rates were also observed in mdx:utr -/- than in WT cardiomyocytes when they were treated with various ferroptosis inducers such as iron overload and the GPX4 inhibitor RSL3. Conclusion: We have deciphered the link between ferroptosis and DMD-CM for the first time. Our data suggest novel targets for the treatment of DMD-CM by inhibiting ferroptosis.
Abstract P1114: Preclinical Large Animal Assessment Of Safety And Engraftment Of Hicms Nanofiber Cardiac Patch Transplantation For Cardiac Repair
Authors: Divya Sridharan, Syed Baseeruddin, Muhamad Mergaye, Orlando Simonetti, Juliet Varghese, Yuchi Han, Robert Hamlin, Heather Powell, Mahmood Khan
Journal: Circulation Research (2023)

Background: Myocardial infarction (MI) is a leading cause of death in the United States. However, none of the therapies can regenerate the damaged heart muscle. Objective: The objective of this study was to assess the safety and engraftment of a nanofiber cardiac patch laden with human iPSC-derived cardiomyocytes (hiCMs) and transplanted in a preclinical porcine MI model. Methodology: MI was induced in pigs via advancing a balloon catheter from the femoral artery into the left anterior descending coronary artery (LAD) below the first diagonal branch (D1) and the balloon was inflated for 90-min to induce myocardial ischemia. Immunosuppressant drug Tacrolimus was given orally one-week before the cardiac patch transplantation and continued for up to 4-weeks post-cardiac patch transplantation. Epicardial transplantation of aligned nanofiber cardiac patch (2 layers) loaded with hiCMs was performed at one-week post MI. Magnetic resonance Imaging (MRI) was performed prior to the MI induction (Baseline), 1-week post-MI and at 4-weeks post cardiac patch transplantation to assess severity of MI and cardiac function. At 4-weeks post-MI, pigs were euthanized, and the heart tissues were processed for immunostaining to confirm the retention and engraftment (Human Nuclear Antibody staining) of the implanted cells in the host myocardium. Results: (a) A significant increase in ST-elevation following 90-min of MI, (b) Incidence of cardiac arrhythmias were not observed post cardiac patch transplantation, confirming the safety of cardiac patch, (c) No teratomas were observed at the transplanted site, indicating safety of terminally differentiated hiCMs and (d) Immunofluorescence staining of cardiac sections in the transplanted cardiac patch area confirmed engraftment of transplanted cells via anti-human nuclear antibody, which demonstrates the survival and engraftment of implanted cells. Conclusions: In summary, we have demonstrated for the first time that aligned nanofiber cardiac patch loaded with hiCMs is safe and can enhance retention of transplanted cells. Further studies are warranted to assess the long-term efficacy of cardiac patch transplantation in improving the cardiac function and to perform first-in-human clinical trials in the near future.
Abstract P3034: Placental Lymphatics In Pregnancy And Preeclampsia
Authors: Benoit Niclou, Sydney Ginn, Lanfang Wang, Giji Joseph, Rebecca D Levit
Journal: Circulation Research (2023)

Background: Preeclampsia is a disease of pregnancy that carries significant maternal morbidity and mortality worldwide with 16% of maternal deaths globally attributed to gestational hypertension. The pathogenesis of preeclampsia is thought to result from inadequate vascular remodeling during placentation with many research efforts focused on studying the anti-angiogenic and pro-inflammatory processes that occur in response to placental ischemia. Hypothesis: Given the known role of lymphatics in mediating inflammation, we hypothesize that insufficient lymphatic proliferation contributes to abnormal placentation and that augmenting lymphangiogenesis may reduce the severity of the disease. Methods: To test this hypothesis, we performed a systematic analysis of human placentas, as well as parietal and basal deciduas. Using immunohistochemistry we stained for lymphatic-specific markers including podoplanin, VEGFC and pan-endothelial marker CD31 and quantified their distribution and morphology. Results: Placentas revealed extensive podoplanin staining within the reticular networks of chorionic villous stromal cells. These same, podoplanin-positive villi, revealed the presence of VEGFC-positive structures. A similar staining pattern was observed in the basal deciduas, where podoplanin-positive decidual cells were found in close proximity to VEGFC-expressing cells. Parietal deciduas on the other hand revealed large lymphatic vessels in the vicinity of the fetal membranes. Conclusion: The abundance of lymphatic specific markers in the placenta and basal decidua hint at the potential existence of a lymphatic-like network within these structures but further functional analyses need to be conducted to understand their role. The dilated lymphatics found in the parietal decidua represent a concrete opportunity to compare lymphatic vessels between preeclamptic and healthy parietal deciduas. An overall better understanding of lymphatics in these tissues may offer new therapeutic strategies for a disease that is in desperate need for adequate treatment options.
Abstract P3155: Cardiac Extracellular Vesicles Mediate The Neoplastic Properties Of Heart Failure
Authors: Tal Caller, Itai Rotem, Olga Shaihov–Teper, Daria Lendengolts, Yeshai Schary, Ruty Shai, Efrat Glick-Saar, Dan Dominissini, Alex Boomgarden, Crislyn D’Souza-Schorey, Nili Naftali Shani, Jonathan Leor
Journal: Circulation Research (2023)

Background: Heart failure (HF) is associated with an increased incidence of cancer independently of shared risk factors. The mechanism behind this link is complex and not entirely clear. We aimed to test the hypothesis that cardiac extracellular vesicles (cEVs) contribute to the link between HF and cancer. Methods &amp; Results: We used a mouse model of heterotopic lung cancer and post-myocardial infarction (MI) HF. To determine the role of cEVs in tumor growth, we focused on cardiac mesenchymal stromal cells (cMSCs) derived EVs, isolated by size exclusion chromatography. cMSCs after MI secreted twice more EVs, characterized with unique proteome, compared to cMSCs from sham-MI ( Fig A, B ). cMSC-EVs from HF harbored more tumor trophic cytokines and microRNA (miR), such as Periostin, Osteopontin, IL-6, TNFα, miR 221, and miR 21. Next, lung cancer cells were inoculated into mice. While HF accelerated tumor growth, EV depletion by GW4869 attenuated this effect. We found that labeled cMSC-EVs targeted lung cancer tumors, and adoptive transfer of cMSC-EVs from failing hearts accelerated tumor growth with and without systemic EV depletion ( Fig C, D ). Finally, we found that spironolactone, a renin-angiotensin-aldosterone inhibitor, mitigated the neoplastic effects of HF, attenuated tumor growth ( Fig E ), and reduced the secretion of cMSC-EVs by 26%. Conclusions: Our results provide new insight into the link between heart failure and cancer. We show, for the first time, that cardiac extracellular vesicles promote tumor growth independently of other secreted factors. Moreover, spironolactone reduces the number of cardiac extracellular vesicles and the neoplastic effects of heart failure.
Abstract P1154: Loss Of Bcl-Rambo Is Protective Against Ischemia-Reperfusion Injury
Authors: Arielys Mendoza, Jason Karch, Pooja J Patel, Dexter Robichaux
Journal: Circulation Research (2023)

Myocardial infarction (MI) is a leading cause of mortality worldwide. Various forms of cell death have been implicated to occur during MI, including apoptosis, necrosis, and autophagic cell death. Unfortunately, death of cardiomyocytes (CMs) in the adult heart is permanent, which demonstrates a need to therapeutically regulate death pathways during MI. To identify novel cell death regulators, we performed a screen in which we exogenously expressed over 13,000 human cDNAs into murine fibroblasts, which were subsequently challenged by a necrotic insult. From these screening efforts, we identified Bcl-Rambo, a B-cell lymphoma 2 (Bcl-2) family member, as a protective regulator against necrosis. We also determined that Bcl-Rambo is the most abundantly expressed Bcl-2 family member in wild-type (WT) mouse heart mitochondria. However, whether Bcl-Rambo is pro- or anti-apoptotic remains controversial in the literature. Recent studies have indicated Bcl-Rambo is a mediator of mitophagy, yet it is unclear how this is connected to its involvement with cell death. To determine the role of Bcl-Rambo in the heart, we generated a novel Bcl-Rambo genetic deletion mouse model and determined that key regulators of mitophagy and mitochondrial fusion are reduced. Additionally, we found that total levels of autophagy are severely blunted in the Bcl-Rambo null heart compared to WT hearts. Furthermore, Bcl-Rambo null mouse embryonic fibroblasts (MEFs) exhibit elongated mitochondria and are susceptible to multiple forms of cell death. Surprisingly, after subjecting these mice to I/R injury, we observed that Bcl-Rambo null hearts exhibit significantly smaller infarct size than their WT counterparts, suggesting that Bcl-Rambo expression is deleterious in this model. In summary, Bcl-Rambo is a unique Bcl-2 family member that regulates mitochondrial dynamics, mitophagy, and cell death. Identifying the diverse roles that Bcl-Rambo plays in mitochondrial health is critical for clinically targeting pathways during MI.
Abstract P1125: Development Of A Multicellular Sinoatrial Node Organoid For Modeling Robust Pacemaking And Conduction
Authors: Young Hoon Son, Christina Sheng, Hee Cheol Cho, Sung-Jin Park
Journal: Circulation Research (2023)

The prevalence and healthcare burden of sinoatrial (SA) node dysfunction have been continuously increasing due to the growth in the elderly population, emphasizing the need for more detailed studies of SA node functions to enable effective therapy for treating and preventing SA node dysfunction. However, current SA node or pacemaker models are limited to isolated single cell-type cells or cell clusters, leaving a gap in the ability to model autonomous cardiac contraction. In contrast, the SA node is a natural organoid with elaborate insulated architecture and heterogeneous cellular composition. Furthermore, current single cell-type pacemakers have worsened heart rhythm stability during one-month in vivo integration, limiting their application as clinically viable biological pacemakers that can generate robust pacemaking and conduction. To address the current limitations of SA node models, we developed a three-dimensional multicellular SA node organoid by reproducing the human SA node's multicellular tissue structure and fail-safe mechanisms. First, inspired by the SA node's partial electrical insulation, we structurally isolated a group of cardiomyocytes with a single exit pathway that allowed for electrical connection to neighboring cardiomyocytes. We found that the geometrically isolated cardiomyocytes successfully activated neighboring quiescent cardiomyocytes without any pacemaker-related gene expression, and they maintained the rhythm for three months. Second, the overexpression of HCN4, a key pacemaker channel, in these isolated cardiomyocytes further improved heart rhythm variability down to the millisecond level, suggesting the interplay between pacemaker gene expression and nodal architecture for long-term, high-fidelity pacing. Finally, we successfully fabricated and integrated the SA node organoid into our 3D pacemaker organoid-myocardium platform, and the integrated organoid dominated rhythm control in 3D cardiac muscle constructs for 30 days. These studies will help define if tissue-level architecture and multicellular compositions mediate SA node's robust pacemaking and conduction and may reveal a high-fidelity tissue-level biological pacemaker as a novel therapeutic strategy for SA node dysfunctions.
Abstract P1013: Identification Of Genetic Links Between Cardiovascular Disease And Insomnia In <i>Drosophila</i>
Authors: Farah Abou Daya, Torrey Mandigo, Matthew Maher, Lily Ober, Dev Patel, James Walker, Richa Saxena, Girish Melkani
Journal: Circulation Research (2023)

Cardiovascular disease (CVD) is the leading cause of death worldwide. CVD is associated with insomnia such that insomnia symptoms double the risk of incident CVD. However, how they are related is unknown. Two recent genome-wide association studies (GWAS) identified genetic loci significantly associated with insomnia, including one locus with five nearby genes that are associated with CVD in an independent GWAS. Therefore, we hypothesized that genetic predisposition to insomnia contributes to the development of CVD. To test this and identify causal genes at this locus, we used Drosophila melanogaster, which are well-established model systems for sleep and cardiac studies. To assess the role of these genes on cardiac physiology, we used the cardiac-specific Hand-Gal4 driver to perform genetic knockdown (KD). One-week-old Drosophila progeny were then used for semi-intact microscopic heart preparation followed by high-speed videography to assess cardiac physiology. Similarly, to assess their role in sleep, we used the neuronal-specific Elav-Gal4 driver to perform KD of these genes. Sleep and locomotor activity of one-week-old flies were monitored using the Drosophila Activity Monitoring System. We found that neuronal and cardiac-specific RNAi KD of four genes conserved in Drosophila: Lsn, ATPSynC, Bruce, and Imp, contributes to compromised sleep and cardiac performance, respectively. Cardiac-specific KD of Lsn led to significant cardiac dilation and reduced fractional shortening, a measure of cardiac performance. KD of ATPSynC led to significantly reduced fractional shortening without dilations. Furthermore, Lsn and ATPSynC KD hearts had disrupted actin-containing myofibrillar organization. Suppression of Lsn increased Pericardin deposition, indicative of fibrosis. Also, the cardiac suppression of ATPSynC and Lsn significantly shortened lifespan. Neuronal-specific KD of three genes significantly disrupted sleep. Furthermore, KD of ATPSynC and Lsn in the heart disrupted sleep in a non-cell-autonomous manner. This work provides novel insights into genetic mechanisms linking CVD and insomnia, highlighting the potential importance of these four genes in the development of both diseases.
Abstract P1018: Peptidyl-prolyl Cis-trans Isomerase-like 4 Is A Novel Regulator Of Smooth Muscle Cell Remodeling
Authors: Batur Gultekin, Kanat Yalcin, Joseph Antonios, Danielle Miyagishima, Zeynep Erson Omay, Tanyeri Barak, Murat Gunel
Journal: Circulation Research (2023)

Introduction: Smooth muscle cell (SMC) remodeling is a complex and multifaceted process that plays an essential role in the maintenance and function of various organ systems in the body. In response to physiological and pathological stimuli, smooth muscle cells exhibit remarkable plasticity, undergoing morphological and functional changes that can impact vascular tone. Dysregulation of SMC remodeling can contribute to the development and progression of numerous pathological conditions, such as hypertension and atherosclerosis. However, the role of SMC remodeling in intracranial aneurysm (IA) formation has yet to be explored. Objective-Method: In this study, we aimed to elucidate the role of PPIL4, an IA-implicated gene, in SMC remodeling using a targeted experimental approach. We performed immunostaining and bulk RNA sequencing (RNA-seq) in human primary brain vascular smooth muscle cells (HPBVSMC) treated with lentiviral shRNA and open-reading-frame (ORF) particles to individually downregulate and overexpress PPIL4, respectively. Results: We found that PPIL4 downregulation results in significant upregulation of the genes encoding contractile proteins, including ACTA2, CNN1, TNNT1, and TNNT2, in HPBVSMC and leads to a significantly increased cell size, favoring a contractile SMC phenotype. Conversely, overexpressing PPIL4 using ORF-lentiviral particles caused downregulation of contractile proteins, increased expression of MMP1 and MMP3, and promoted a synthetic phenotype in SMCs. Furthermore, PPIL4 overexpression caused cell elongation and spindle-like cell formation in HPBVSMC. Conclusion: In conclusion, our findings highlight the critical role of PPIL4 in modulating SMC remodeling, suggesting a potential mechanistic link between PPIL4 dysregulation, SMC remodeling, and IA formation, which warrants further investigation.
Abstract P1016: Single Cell Transcriptomic Analysis Of Tafazzin Knockout Mice For Pathway And Therapeutic Discovery In Barth Syndrome
Authors: Gayani Perera, Liam Power, Amy Larson, Christina Codden, Junya Awata, Rebecca Batorsky, Douglas Strathdee, Michael T Chin
Journal: Circulation Research (2023)

Barth Syndrome, a rare X-linked disorder affecting 1:300,000 live births, results from defects in Tafazzin, an acyltransferase that remodels cardiolipin and is essential for mitochondrial respiration. Barth Syndrome patients develop cardiomyopathy, muscular hypotonia and cyclic neutropenia during childhood, rarely surviving to middle age. At present, no effective therapy exists and downstream transcriptional effects of Tafazzin dysfunction are incompletely understood. To identify novel, cell-specific pathological pathways downstream of Tafazzin that mediate heart dysfunction, we performed snRNA-seq on mouse hearts deficient in Tafazzin. We generated libraries from four WT and four KO mouse hearts (10X Genomics Chromium) and performed next generation sequencing (Illumina NovaSeq S4), demultiplexing (CellRanger), doublet reduction (DoubletFinder), ambient RNA removal (SoupX), sample integration (Harmony), optimal clustering (ChooseR/Seurat), determined differentially expressed genes (DEGs; DESEQ2), and inferred a predicted cell-cell communication network (scLR). Surprisingly, DEGs were distributed heterogeneously, with cardiomyocytes, adipocytes, endothelial cells, fibroblasts and macrophages exhibiting the greatest number of DEGs between each genotype, while lymphocytes, lymphatic endothelium, pericytes, smooth muscle cells and mesothelial cells were mostly unaffected. Gene Ontology analysis showed cell specific effects such as altered amino acid and carbohydrate metabolism plus altered ion channel function in cardiomyocytes and common metabolic perturbations across all affected cell types. Analysis of Ligand-Receptor pair expression, to infer intercellular communication patterns, revealed WT adipocytes form the densest intercellular communication network, followed by WT cardiomyocytes. In the Tafazzin KO hearts, adipocyte significant intercellullar communication ceases, primarily through loss of PDGFRB interactions, while cardiomyocytes remain largely unperturbed. These findings suggest that adipocyte mitochondria may be most sensitive to mitochondrial Tafazzin deficiency and rescuing adipocyte mitochondrial dysfunction may provide therapeutic benefit in Barth Syndrome patients.
Abstract P1012: Wnt Signaling Is Required For Myxomatous Valve Disease In A Mouse Model Of Marfan Syndrome
Authors: Na Xu, Christina Alfieri, Katherine Yutzey
Journal: Circulation Research (2023)

Introduction: Myxomatous valve disease (MVD) is the most common cause of mitral regurgitation, characterized by valve leaflet thickening and progressive valve degeneration, leading to impaired cardiac function and heart failure. MVD in a mouse model of Marfan syndrome (MFS) includes valve leaflet thickening and increased immune cell infiltration. However, the underlying mechanisms by which immune cells are recruited in MFS valves remain undefined. Hypothesis: Inhibition of Wnt signaling prevents immune cell recruitment and MVD progression in MFS valves. Methods: Mice with the mutation of Fibrillin 1 ( Fbn1 C1039G/+ ) recapitulate histopathological features of MFS and Wnt signaling activity was detected in TCF/Lef-lacZ reporter mice. The expression level of C-C motif chemokine ligand 2 (CCL2) was detected in Fbn1 C1039G/+ mice by qPCR and RNAscope. Inhibition of Wnt signaling was achieved by conditional induction of the soluble Wnt inhibitor Dkk1 in periostin-expressing valve interstitial cells of Periostin-Cre; tetO-Dkk1; R26rtTA; TCF/Lef-lacZ; Fbn1 C1039G/+ mice. Dietary doxycycline was administered for one month beginning with MVD initiation (1-month-old) or MVD progression (2-month-old). Histological evaluation and immunofluorescence for immune cells were performed. Results: Wnt signaling as detected by TCF/Lef-lacZ reporters and CCL2 expression were upregulated early in mitral valve disease progression, prior to immune cell infiltration in Fbn1 C1039G/+ mice. Inhibition of Wnt signaling by Dkk1 induction at 1-month of age prevented the induction of myxomatous mitral valve disease, indicated by reduced valve leaflet thickness with decreased CD45+ leukocytes and CCR2+ immune cells in Fbn1 C1039G/+ mice. However, later Wnt inhibition starting at 2 months when inflammation and myxomatous changes are occurring did not prevent the progression of myxomatous mitral valve disease. Conclusions: Wnt signaling is involved in the initiation of mitral valve abnormalities and inflammation, but is not responsible for valve disease progression once it has been initiated.